The main objective of the proposed research is to described how humans process auditory stimuli. The research is carried out in the framework of an information processing model of the sequence of stages between the sound stimulus and meaning in the mind of the observer. The research paradigms include speech and nonspeech perception experiments. Factorial designs and functional measurement techniques are used to determine the acoustic features of speech sounds and how the features are combined and integrated in speech perceptoin. Listeners are asked for continuous rather than discrete judgments to provide a more direct assessment of the nature and utilization of featural information. Phonological context will be varied simultaneously with the variation of acoustic featural information to assess how higher-order context is integrated with featural information in speech perception. This experimental framework will be extended to studies of the similarities and differences in the perception of speech and nonspeech signals.